<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./00-demo.js"></script>
    <script src="./00-demo1.js"></script>
    <script>
        // 在浏览器中，没有模块级别作用域
        console.log(hero);
        song();
    </script>

</head>

<body>

</body>

</html>